Superheat-regulating device



July 29, 1930. v, E, ALDE N 1,771,699

SUPERHEAT REGULAT ING DEVI CE Filed May 29, 1925 2 Sheets-Sheet 1INVENTOR V01 6'. who

ATTORNEYS V. E. ALDEN SUPERHEAT REGULATING DEVICE July 29, 1930.

Filed May 29, 1925 2 Sheets-Sheet 2 INVENi'OR w QM,

AT TORN EYS Patented July 29, 19 30 UNITED S ATES PATENT VERN E. ALDEN,OF BALTIMORE, MARYLAND, ASSIGNOB TO THE BABCOQK & WILCOX COMPANY, OFBAYONNE, NEW JERSEY, A CORPORATION OF NEW JERSEY SUPERHEAT-REGULATINGDavida Application filed lllay 29,

My present invention relates to superheat ers provided with regulatingdevices by which which the degree of "superheat delivered fronf thesuperheater may be regulated. ,My invention willbe best understood fromthe following descriptipn and the annexed drawings, in which Fig. 1 isan outside view of a separately fired superheater, with some of the\parts broken away and embodying an illustrative form of my invention;Fig.

2 is an enlarged view, with some of the parts broken away, of a portionof Fig. 1 and Fig.

3 is an enlarged view of a portion of Fig. 1.

Like reference characters indicate like.

In the illustrative arrangement, I have shown a separately firedsuperheater having a casing 10 andbanks of tubes 11, the tubes of thesebanks being inverted U-tubes connected to the lower drums 12 with asteam inlet pi e 13 connected to the rear-most drum 12 and t e frontbank of tubes 11 being connected to a superheater outlet pipe 14. Thesuperheater is fired, in the illustrative form by an underditions in apower plant will vary from time feed stoker 15 and the casing 10 mayalso be 7 provided with a steam generating apparatus in the form of awater tube boiler, the drum, 16 indicating 'a portion of such a separatesteam generating apparatus. Since such an apparatus, however, may beused or not, as desired, and is no part of my present invention, furtherdescription thereof will be unnecessary. The superheater which I haveshown, is of a'well known type, but I have shown it merel for purpose ofillustration, since the speci 0 form of superheater is no part of mypresent invention. It will be understood that in the form of superheaterillustrated, steam from one or more steam generators or fromintermediate stages of asteam turbine 01-, any other source,

flows through the inlet pipe 13 and from thencethrough the tubes 11 andthe drums 12 to the superheater outlet 14, such steam,wh1'ch may besaturated steamwhen it enters the superheater, being raised to a highdegree of superheat in its passage through the superheater.

As is well understood, the operating con- 1925. Serial No. 38,721.

to time, so that without provision to that end,

OFFICE the superheat in the steam delivered through the pipe 14 willvary considerably, and this will cause serious operating difficulties,particularly if, as is usually the case, it Is desired to maintain thesuperheat at as high a point as may be without exceeding a predeterminedlimit which would cause operating difiiculties.

It has heretofore been proposed to regulate the superheat by injectinwater into the steam after it has passed the superheater. This, however,presents a number of difiiculties. For instance, where the superheatedsteam is supplied to turbines, it is particularly desirable'that noWater shall enter the turbines. When water is injected into thesuperheated steam between the superheater and that some water will passinto the turbine. This difilculty has heretofore been controlled largelyby spraying the water into the Steam, but obviously the maintenance ofthese sprays and the insurance that the spray will be fine enough tomake certain the evaporation of all of the water adds to the operatingdifliculties.

In in present arrangement, I overcome these dlfliculties by admittingwater to the steam entering the superheater in accordance with theoperating conditions, so that the de gree of superheat in thesteamleaving the superheater can be maintained substantially constant.Furthermore, it will be obvious that by thus introducingthe-water, itsevaporation will be insured as it is carried through the superheater, sothat fine spraying of the water will not be necessary.

Preferably, I arranged my apparatus ,so

that the amount ofwater admitted to the steam at the inlet sideof' thesuperheater will be in accordance with the temperature of the steam atthe superheater outlet. In other words, if the superheat in the outlettends to rise, thanI admit water into the inlet side, and if thequantity thus admitted is not sulficient to bring the superheat down tothe de sired int, then a greater rate of flow of water 1s set up in theinlet side until the additional quantity of'water to be evaporated inthe superheater will bring the degree oferator will be guided in suchadmission.

Preferably, however, I provide an automatic means for admitting theWater to be controlled by devices ldcated in the superheater outlet, sothat the quantity of water admitted will be automatically determined bythe conditions in this outlet.

As an illustrative form of such automatic arrangement, I have shown anapparatus which is described more in detailin the copending applicationof David S. J acobus, Serial No. 7 48,885, filed November 10, 1924, butit will beunderstood that any other form of temperature controlledapparatus may be used for this automatic control.

In the arrangement described, a valve body 17 is provided with aplurality of ports 18,

each having a valve 19 cooperating therewith, this valve body 17 beinglocated in a .water supply pipe 20 having its outlet 21 entering theupper part of a vertical portion 22 of the superheater inlet pipe thispipe preferably being provided with a long bend between the verticalportion and the superheater drum 12.

The pipe 20 may be provided with a number of small openingsin its lowerportion so that water passing through the pipe 20 will fall downward inthe vertical section 22.

- With my arrangement, however, it will be un-' necessary to attempt tospray this water into fine drops.

In the vertical section 22 I have provided a ,pluralit of waterspreading devices in the form 0 screens held between the sections of thepipe, these screens serving to receive the 4 water from the pipe 20 andspread it over a vice may be widely varied, the form shown hebetweenwhich is wire screen secti0ns, 23 eld a mass 24' of small bodies whichmay be of any desired material. It will be understood that if thescreening effect is not desired, then the water may caused to flow downover any extended surfaces positioned inthe pipe so as to contacted bythe inflowin steam.

The valves 19 may operated independently and it will be obvious that inthe arrangement of the valve body 17, as defined in ing a pair of heaFig. 2, the amount of-water which will flow rangement'is no part of mypresent invention,

from right to left through the valve body These screens also will bedetermined by the number of valves 19 which are opened. While thesevalves 19 may be operated by hand, I prefer to operate themautomatically, and in the arrangement shown, each valve 19 has a stem25, to which is attached a soft iron core 26 moving in a solenoid 27.The valves are normally held closed by a spring 28, the height of thelift of the valves being controlled by the contact between the top ofthe core 26 and the bottom of a hollow body 30 surrounding the upper endof the stem 25 and whose position is controlled by a screw 29 connectedto some fixed part.

tacle 31 containing an expansible fluid which In the superheater outletpipe 14 is a recep is connected through a pipe 32 to a vertical tube 33,in the Walls of which are inserted electric contact points, the tube 33being filled with mercury, the height of which, of course, will bedetermined by the temperature of the receptacle 31, which, in turn willbe determined by the temperature of the steam leaving the superheater.There may be as many of-the contacts as desired, each being in ir cuitwith one of the solenoids 27 and asource of energy. It will besuificientto describe one of these circuits, the contact member 34 of which isconnectedthrough the wire 35 with one of the solenoids 27, the otherside of the solenoid being connected through the wire 36 with the wire37, the battery 38, the wire 39 and a contact point 4Q at the bottom ofthe tube 33. 1 As the temperature of the steam in the outlet rises, themercury column in the tube 33 will also rise and when it reaches thecontact 34, a circuit is formed between the contacts 40 and 34 and thewiring connected thereto to open the valve connected with the solenoid27 in that circuit.

It will be understood that in the illustrative form, the mercury inrising to the contact 34 will have successively risen to the lowercontacts and will have therefore successively opened the valves 19 incircuit therewith, so

that, in the illustrative form, when the mercury reaches the contact 34,all of the valves will have been opened. 1

Obviously, similarly, as the temperature in the superheated steam beginsto dro' the mercury in the tube 33 will also drop an thus the valves 19willbe closed one at a timeIto shut off the water until the desiredbalance is reached.

In order to prevent disaster through failure of the water suppliedthrough the pipe-21 to i keep the superheat within the desired limits,

in the arrangement shown, there is a contact 40' atthevupper part of thetube 33' which, when the mercury reaches it, closes a circuit through.an operating device'for a water ops erated motor 41 to open doors 42 inthe setting to permit air to pass directlyinto the setting to cool thesuperheater tubes '11. Such arand further description thereof will beun- ,1. In a superheat regulating device, a'

superheater, an inlet pipe therefor, means to admit water into saidinlet pipe, and water spreading devices in said inlet pipe between t esuperheater and the point of admission of the water, whereby the wateris spread over surfaces contacted by the steam beforev entering thesuperheater.

admit water into said inlet superheater, an inlet 2. In a superheatregulating device, a superheater, an inlet pipe therefor, means to(pipe, said pipe having a vertical portion, an water spreading devicesin sai vertical portion between the superheater and the point ofadmission of the water, whereby the water is spread ,over surfacescontacted by the steam before entering the superheater.

I 3. In a superheat regulating device, 'a i e therefor, means to admitwater into sai inlet pipe, said pipe having a vertical portion into theupper part of which the water is admitted, and water spreading devicesin said vertical portion and positioned to receive the water so admittedand to be contacted by the steam flowing to said superheatera 4. In asuperheat regulating device, a superheater, an inlet pipe therefor,means to admit water into sai inlet pipe, said pipe having a verticalportion into the upper part of which the water is admitted, and ascreenin said vertical portion and positioned to receive the water so admittedand adapted to permit the steam flowing to said superheater to flowtherethrough.

5. In asuperheat regulating device, a superheater, an inlet pipetherefor, means to admit water into said inlet pipe in relatively largemasses, and water spreading devices in said. inlet pipe between the; sup,erheater and the point of admissionf'of the water to spread such massesover an extended surface contacted by-the steam flowing to thesuperheater.

6. In a superheat regulating device, a superheater, an inlet pipetherefor, means to admit water into said inlet pipe in relatively largemasses, said pipe having a vertical portion, and a screen in saidvertical portion beneath the point of admission of the masses of waterand positioned to receive the same and to permit e steam flowing to thesuperheater to pass through the same and contact with the water therein.

7. In a superheat regulatin device, a superheater having an inlet an anoutlet,

I means to admit water into said inlet comprising a water delivery pipe,a water supply pipe and amultiple-ported valve'body connecting the twopipes, each port having a separately-openable valve therefor, means foropening said valves successively.

8. Ina su erheat regulating device for a superheater aving an inlet andan outlet,

means to admit water into said inlet, compris-- ing a waterdeliverypipe, a water supply pipe and a multiple-ported valve body connectingthe two pipes, each port having a separately-openab e valve therefor, athermostat in said outlet and means operated by said thermostat to opensuccessively said valves as the temperature of the superheated steam atsaid outletincreases.

9. In a su erheat regulating device for a superheater aving an inlet andan outlet, means to admit water,into said inlet, comprising awater'delivery pipe, a water supply pipe and a multiple-ported valvebody connecting the two pipes, each port having a separately-openab evalve therefor, (and a thermostat in said outlet, solenoids to open eachof said valves, and electric circuits each containing one of saidsolenoids and arranged to be energized successively by said thermostat.

10. In a su erheat regulating devicefor asuperheater aving an inlet andan outlet, means to admit water to said inlet, a thermostat in. saidoutlet, electric circuits for operating successively water-admittingmeans and controlled by said thermostat, whereby the quantity of wateradmitted is increased and as said electric circuits are successivelyoper-' ated.

11. In a superheat regulatin device, a superheater havin an inlet an apipe adapted to ischarge water into said inlet, a plurality ofvalvescontrolling the discharge of said water and means to operate thevalves successively upon changes in the heat of the steam in saidoutlet.

YERN E. ALDEN.

*no an outlet.

